ABSTRACT

Strategies for studying individuals across the life-span have been changing in the last decade because of accumulating evidence about the flexibility of humans in responding to environmental alterations. Adaptation to social content is a central feature of the life-span perspective. Until recently, acceptance of this perspective has been hampered by three premises about development (Lerner, 1985). First, development was thought to shape individuals in such a way that later change, whereas possible, was difficult to initiate. Early experiences were believed to foreclose most chances of altering one’s developmental trajectory. Second, development was seen as essentially a “within-the-person phenomenon,” with social context having a relatively small impact. Third, development was thought to proceed in a fairly standard sequence for all persons; individual differences in life courses and the existence of various multidetermined developmental paths were not a focus of study. Research has demonstrated that change occurs across the life-span, that developmental life courses are not entirely determined by early childhood experiences, and that contextual features both enhance and constrain the potential for change, the end result being an alteration in all three beliefs (Baltes & Brim, 1979, 1980, 1981; Baltes & Nesselroade, 1973; Brim & Kagan, 1980; Gollin, 1981).